I have a question about this summation:
$$\sum_{i} ((i+1)^2)$$ where $\{i \in S| f:\mathbb{Z}\rightarrow S, f(x)=x\%5 \}$
How would I go about determining the upper limit of $i$? Does this mean that the sum is from $i=0$ to $i=5$, since the remainder of any integer when divided by $5$ will be between $0$ and $5$?